Publications by authors named "Seok Ahn"

Climate change has significantly affected the subalpine ecosystems, leading to mass die-offs of the Korean fir tree, a key climate-sensitive species in these environments. Proactive analysis of the phenotypic responses of these trees to climate change or the establishment of preemptive strategies for trees to adapt to these environmental changes remains a challenge. The current study aimed to investigate the impact of climate change on the health of Korean fir (Abies koreana) in the subalpine ecosystem of Jirisan Mountain, South Korea.

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Article Synopsis
  • - This study focused on advanced lung adenocarcinoma patients without EGFR mutations or ALK fusions, highlighting their poor survival outcomes compared to those who have targeted therapies.
  • - Researchers compared clinical outcomes between patients who participated in clinical trials and those who received standard care from 2017 to 2022, using a method called propensity score matching to ensure balanced groups.
  • - Results showed that clinical trial participants had significantly better survival rates, with a median overall survival of 27.3 months compared to 17.1 months for those receiving standard care, indicating a 29.6% reduced risk of death for clinical trial participants.
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Groundwater quality management is pivotal for ensuring public health and ecological resilience. However, the conventional water quality indices often face challenges related to parameter selection, geographic coverage, and scalability. The integration of machine learning and spatial analysis represents a promising methodological shift, allowing for high accuracy and adaptive management strategies.

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Aims: To introduce the admission protocol of a COVID-19 specialized hospital outlined by the government, including the assessment of reverse transcription polymerase chain reaction (RT-PCR), low dose chest computed tomography (CT) and antigen-detecting rapid diagnostic test (Ag-RDT) for patient screening.

Materials And Methods: This was a retrospective cohort study of 646 patients who were admitted between December 2020, and February 2021, during the third wave of COVID-19 in Korea. Ag-RDT and RT-PCR were routinely performed on all patients who required admission, and low-dose chest CT was performed on high-risk patients with associated symptoms.

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Flow cytometry is a promising tool used to identify the phenotypic features of bacterial communities in aquatic ecosystems by measuring the physical and chemical properties of cells based on their light scattering behavior and fluorescence. Compared to molecular or culture-based approaches, flow cytometry is suitable for the online monitoring of microbial water quality because of its relatively simple sample preparation process, rapid analysis time, and high-resolution phenotypic data. Advanced statistical techniques (e.

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The metacommunity approach provides insights into how the biological communities are assembled along the environmental variations. The current study presents the importance of water quality on the metacommunity structure of algal communities in six river-connected lakes using long-term (8 years) monitoring datasets. Elements of metacommunity structure were analyzed to evaluate whether water quality structured the metacommunity across biogeographic regions in the riverine ecosystem.

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Benign prostatic hyperplasia (BPH) is one of the most common chronic diseases in male population, of which incidence increases gradually with age. In this study, we investigated the effect of chrysophanic acid (CA) on BPH. BPH was induced by a 4-week injection of testosterone propionate (TP).

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Constitutive activation of signal transducer and activator of transcription 3 (STAT3) is frequently observed and closely linked with proliferation, survival, metastasis and angiogenesis of various cancer cells, and thus its inhibition can be considered a potential therapeutic strategy. We found that 3-formylchromone (3FC) inhibited both constitutive and inducible STAT3 activation in multiple myeloma (MM) cells. Besides the inhibition of STAT3 phosphorylation, 3FC also abrogated constitutive activity and nuclear translocation of STAT3.

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Ginsenosides can be classified on the basis of the skeleton of their aglycones. Here, we hypothesized that the sugar moieties attached to the dammarane backbone enable binding of the ginsenosides to the sweet taste receptor, eliciting glucagon-like peptide-1 (GLP-1) secretion in the enteroendocrine L cells. Using the human enteroendocrine NCI-H716 cells, we demonstrated that 15 ginsenosides stimulate GLP-1 secretion according to the position of their sugar moieties.

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Background And Objectives: It has been demonstrated that the anomalous origin of coronary arteries (AOCA) are generally asymptomatic and rare diseases. However, some cases can cause severe life threatening events. To detect these anomalies, coronary angiographies and autopsies were used to detect coronary artery anomalies, but these procedures have limitations because of their invasiveness.

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Xanthomonas oryzae pv. oryzae (Xoo) is a plant bacterial pathogen that causes bacterial blight (BB) disease, resulting in serious production losses of rice. The crystal structure of malonyl CoA-acyl carrier protein transacylase (XoMCAT), encoded by the gene fabD (Xoo0880) from Xoo, was determined at 2.

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Membranous lipodystrophy is characterized by the presence of microcysts lined by amorphous, eosinophilic material with an arabesque appearance. We experienced a case of a 72-year-old man who had dark brownish, pruritic papules on the arms, legs, and back. Histopathologic examination of a biopsied lesion showed homogeneous, eosinophilic material in the papillary dermis, as well as membranous lipodystrophy.

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Background: The aims of this study are to examine the prevalence of chronic kidney disease (CKD) with metabolic syndrome (MS) and to investigate the association between CKD and MS after adjustment for socioeconomic position and health behavior factor.

Methods: The random sample used in this study included 5136 Korean subjects ≥20 years of age. We divided the subjects into two groups based on the presence of MS, for which the criteria described in the NCEP ATP III and International Diabetes Federation were used.

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Statement Of Problem: A number of studies about the nano-treated surfaces of implants have been conducting along with micro-treated surfaces of implants.

Purpose: The purpose of this study was to get information for the clinical use of nano-treated surfaces compared with micro-treated surfaces by measuring removal torque and analyzing histological characteristics after the placement of various surface-treated implants on femurs of dogs.

Material And Methods: Machined surface implants were used as a control group.

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Background: The N-terminal fragment of pro Brain Natriuretic Peptide (NT-pro BNP) is a neuro-hormone synthesized in the cardiac ventricles in response to increased wall tension. The purpose of this study was to assess the correlation between the NT-pro BNP levels and the New York Heart Association function class (NYHA Fc) of dyspnea and echocardiographic findings for the patients who visited our cardiology departments.

Methods: From October, 2002 to April, 2003, serum NT-pro BNP levels were measured in 348 patients who visited the Samsung Medical Center and the Jong Koo Lee Heart Clinic.

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Head-up tilt testing (HUT) is a useful diagnostic tool for evaluating suspected neurocardiogenic syncope. Although arrhythmic events during HUT have been occasionally reported, their incidence in a large number of patients is unknown. We aimed to assess the incidence and clinical significance of arrhythmic events in patients with suspected neurocardiogenic syncope who underwent HUT with isoproterenol provocation.

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For the evaluation of efficacy of cardiopulmonary exercise testing, we compared New York Heart Association functional class with peak oxygen consumption rate (VO(2)peak) in 31 patients with severe mitral regurgitation who underwent mitral valve repair surgery. One year later, the VO(2)peak values did not show significant improvement; however, the patients who had more than a mild degree of residual mitral regurgitation (n = 14) after 1 year of surgery had a VO(2)peak value that was significantly decreased (from 22.7 +/- 6.

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To evaluate the status of intestinal protozoan infections in inhabitants of Gangweon-Do, Korea, a total of 1,310 stool specimens (male 669, female 641) was collected from 2 cities and 3 counties. They were examined routinely 1 time by the method of formalin-ether sedimentation technique. The results were as follows: 1.

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A study was carried out to figure the cases and to observe the endemic status of clonorchiasis and metagonimiasis in endemic areas in Korea. Total 13,373 inhabitants living in 40 villages along 7 main rivers and 9 small streams were subjected to stool examination. They were selected randomly among the riverside population.

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